Yes, filtered water can be good for watering plants, depending on the type of filter and the quality of the water you’re starting with. While plants need clean water to thrive, not all water filters are equal in what they remove. Let’s break down how filtered water can affect your plants and what to keep in mind.
Benefits of Using Filtered Water for Plants
1. Removal of Harmful Chemicals
Many municipal water supplies contain chlorine or chloramine, both of which are added to kill bacteria. While these chemicals are safe for humans, they can be harmful to plants, particularly delicate ones. Filtered water, especially water processed by carbon filters, can remove these chemicals, providing healthier water for plant roots.
2. Better Growth in Sensitive Plants
Plants like houseplants, orchids, and herbs often respond better to filtered water because it doesn’t have the chemicals or salts that might stunt their growth. Chlorine and heavy metals (like lead or copper) can damage sensitive plants over time, leading to browning leaves, reduced growth, or root damage.
3. Improved Soil Health
Using filtered water reduces the buildup of salts and minerals in the soil, which can happen over time with untreated tap water. This is particularly beneficial if you live in an area with hard water (high in calcium and magnesium). Softened water, which often contains sodium, is also not ideal for plants, as too much salt can damage roots. Filtered water solves both of these problems.
4. Cleaner Water for Indoor Plants
Indoor plants don’t have the luxury of natural rainwater, so giving them clean filtered water mimics rainwater’s pureness, free from harsh chemicals, ensuring better hydration and nutrient absorption.
Which Filtered Water is Best?
Different types of filtered water can be beneficial for plants, but it depends on the filter system and what is being removed:
- Carbon-Filtered Water:
- Removes: Chlorine, some heavy metals, and contaminants.
- Good for: Most plants, especially those sensitive to chlorine or city water additives.
- Reverse Osmosis (RO) Water:
- Removes: Almost all contaminants, minerals, and salts.
- Best for: Very sensitive plants or areas with extremely hard water.
- Note: RO water lacks minerals, which some plants need. You may need to supplement with plant fertilizers if using RO water exclusively.
- Distilled Water:
- Removes: Everything, including beneficial minerals.
- Best for: Short-term use, hydroponics, or very delicate plants.
- Note: Like RO water, it’s too “pure” for long-term use unless you add nutrients back in.
Things to Consider
- Don’t Overdo It: While filtered water can be great for most plants, it’s important to ensure that they’re still getting enough nutrients from the soil. If you’re using something like reverse osmosis or distilled water, you might need to supplement the soil with minerals and nutrients that the water isn’t providing.
- Rainwater Is Best: If possible, use rainwater for plants. It’s naturally soft, free of chemicals, and often the best option for plant health. You can collect it in barrels and use it to water both indoor and outdoor plants.
- Watch for Over-Filtration: With RO or distilled water, you run the risk of leaching essential nutrients from the soil over time. Plants, especially outdoor ones, benefit from some minerals in their water (like calcium and magnesium). Regular tap water can often provide these in small amounts.
Final Thoughts
Filtered water can be very beneficial for plants, especially those that are sensitive to harsh chemicals like chlorine, or for households with hard water. However, if you’re using reverse osmosis or distilled water, you may need to supplement your plants with extra nutrients to make up for the lack of minerals in the water. For most situations, carbon-filtered water is an ideal balance, removing harmful chemicals while keeping beneficial minerals intact.
So, if you have a water filter at home, it’s a great idea to use it for your plants—just keep an eye on their overall health and adjust if needed!